Snapd triggers system shutdown

Hi, I have Ubuntu Core running on a Gateway Type Unit with snap refreshes enabled from the stable channel.
On one unit, the system shutdown and did not restart until it was manually power cycled.I would like to find out what was the reason the system decided to shutdown. Maybe someone can help me. Here is the syslog extract from before and after the restart:

Dec 9 06:25:02 3XHCN42 CRON[32629]: (CRON) info (No MTA installed, discarding output)
Dec 9 06:25:55 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 06:58:28 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 31 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 06:59:09 3XHCN42 systemd-timesyncd[1498]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com).
Dec 9 06:59:31 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 07:16:19 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 16 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 07:17:01 3XHCN42 CRON[3502]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 07:17:22 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 08:16:10 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 56 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 08:17:01 3XHCN42 CRON[7095]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 08:17:13 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 09:16:01 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 56 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 09:17:01 3XHCN42 CRON[10683]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 09:17:04 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 10:16:55 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 57 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 10:17:01 3XHCN42 CRON[14277]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 10:17:58 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 10:44:13 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 25 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 10:44:47 3XHCN42 systemd[1]: Starting Message of the Day…
Dec 9 10:44:47 3XHCN42 systemd[15938]: motd-news.service: Failed at step EXEC spawning /etc/update-motd.d/50-motd-news: No such file or directory
Dec 9 10:44:47 3XHCN42 systemd[1]: motd-news.service: Main process exited, code=exited, status=203/EXEC
Dec 9 10:44:47 3XHCN42 systemd[1]: Failed to start Message of the Day.
Dec 9 10:44:47 3XHCN42 systemd[1]: motd-news.service: Unit entered failed state.
Dec 9 10:44:47 3XHCN42 systemd[1]: motd-news.service: Failed with result ‘exit-code’.
Dec 9 10:45:16 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 11:16:46 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 30 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 11:17:01 3XHCN42 CRON[17868]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 11:17:49 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 11:40:55 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 22 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 11:41:51 3XHCN42 snapd[1947]: storehelpers.go:436: cannot refresh: snap has no updates available: “alsa-utils”, “bluez”, “caracalla”, “caracalla-kernel”, “ccm-wda”, “core”, “dcc”, “dcm”, “locationd”, “modem-manager”, “network-manager”, “tpm2”, “udisks2”, “uefi-fw-tools”, “wifi-ap”, “wpa-supplicant”
Dec 9 11:41:51 3XHCN42 snapd[1947]: autorefresh.go:397: auto-refresh: all snaps are up-to-date
Dec 9 11:41:58 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 12:07:10 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 24 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 12:07:55 3XHCN42 ModemManager[1891]: Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connected -> registered)
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7753] (cdc-wdm0): modem state changed, ‘connected’ --> ‘registered’ (reason: user-requested)
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7755] device (cdc-wdm0): state change: activated -> failed (reason ‘modem-no-carrier’) [100 120 25]
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7761] manager: NetworkManager state is now CONNECTED_LOCAL
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7765] manager: NetworkManager state is now DISCONNECTED
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7896] device (cdc-wdm0): Activation: failed for connection ‘cellularModem’
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.7974] device (cdc-wdm0): state change: failed -> disconnected (reason ‘none’) [120 30 0]
Dec 9 12:07:55 3XHCN42 NetworkManager[1926]: [1575893275.8086] dns-mgr: Removing DNS information from /sbin/resolvconf
Dec 9 12:07:55 3XHCN42 systemd[1]: Starting Update resolvconf for networkd DNS…
Dec 9 12:07:55 3XHCN42 sh[20913]: sed: can’t read /run/systemd/netif/leases/: No such file or directory
Dec 9 12:07:56 3XHCN42 NetworkManager[1926]: [1575893276.1162] policy: Device ‘cdc-wdm0’ has no connection; scheduling activate_check in 10 seconds.
Dec 9 12:07:56 3XHCN42 sh[20913]: sed: can’t read /run/systemd/netif/leases/
: No such file or directory
Dec 9 12:08:05 3XHCN42 sh[20913]: message repeated 8 times: [ sed: can’t read /run/systemd/netif/leases/: No such file or directory]
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9349] policy: auto-activating connection ‘cellularModem’
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9382] device (cdc-wdm0): Activation: starting connection ‘cellularModem’ (8490d104-d8fd-423d-b4c2-cc4b149748ed)
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9388] device (cdc-wdm0): state change: disconnected -> prepare (reason ‘none’) [30 40 0]
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9393] manager: NetworkManager state is now CONNECTING
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9409] device (cdc-wdm0): state change: prepare -> need-auth (reason ‘none’) [40 60 0]
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9495] device (cdc-wdm0): state change: need-auth -> prepare (reason ‘none’) [60 40 0]
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Simple connect started…
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Simple connect state (4/8): Wait to get fully enabled
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Simple connect state (5/8): Register
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Simple connect state (6/8): Bearer
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Simple connect state (7/8): Connect
Dec 9 12:08:05 3XHCN42 ModemManager[1891]: Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
Dec 9 12:08:05 3XHCN42 NetworkManager[1926]: [1575893285.9596] (cdc-wdm0): modem state changed, ‘registered’ --> ‘connecting’ (reason: user-requested)
Dec 9 12:08:06 3XHCN42 sh[20913]: sed: can’t read /run/systemd/netif/leases/
: No such file or directory
Dec 9 12:08:09 3XHCN42 sh[20913]: message repeated 3 times: [ sed: can’t read /run/systemd/netif/leases/: No such file or directory]
Dec 9 12:08:09 3XHCN42 ModemManager[1891]: Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> connected)
Dec 9 12:08:09 3XHCN42 ModemManager[1891]: Simple connect state (8/8): All done
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.7881] (cdc-wdm0): modem state changed, ‘connecting’ --> ‘connected’ (reason: user-requested)
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.7972] device (cdc-wdm0): state change: prepare -> config (reason ‘none’) [40 50 0]
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8012] device (cdc-wdm0): state change: config -> ip-config (reason ‘none’) [50 70 0]
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8045] (cdc-wdm0): IPv4 static configuration:
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8057] address 10.130.30.243/24
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8069] gateway 10.130.30.1
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8080] DNS 10.193.0.114
Dec 9 12:08:09 3XHCN42 systemd-timesyncd[1498]: Network configuration changed, trying to establish connection.
Dec 9 12:08:09 3XHCN42 systemd-networkd[676]: wwan0: Gained IPv6LL
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8324] device (cdc-wdm0): state change: ip-config -> ip-check (reason ‘none’) [70 80 0]
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8400] device (cdc-wdm0): state change: ip-check -> secondaries (reason ‘none’) [80 90 0]
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8439] device (cdc-wdm0): state change: secondaries -> activated (reason ‘none’) [90 100 0]
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8459] manager: NetworkManager state is now CONNECTED_LOCAL
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8588] manager: NetworkManager state is now CONNECTED_GLOBAL
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8606] policy: set ‘cellularModem’ (wwan0) as default for IPv4 routing and DNS
Dec 9 12:08:09 3XHCN42 NetworkManager[1926]: [1575893289.8621] dns-mgr: Writing DNS information to /sbin/resolvconf
Dec 9 12:08:10 3XHCN42 NetworkManager[1926]: [1575893290.0786] device (cdc-wdm0): Activation: successful, device activated.
Dec 9 12:08:10 3XHCN42 sh[20913]: sed: can’t read /run/systemd/netif/leases/
: No such file or directory
Dec 9 12:08:13 3XHCN42 sh[20913]: message repeated 3 times: [ sed: can’t read /run/systemd/netif/leases/: No such file or directory]
Dec 9 12:08:13 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 12:08:14 3XHCN42 sh[20913]: sed: can’t read /run/systemd/netif/leases/
: No such file or directory
Dec 9 12:08:25 3XHCN42 sh[20913]: message repeated 11 times: [ sed: can’t read /run/systemd/netif/leases/*: No such file or directory]
Dec 9 12:08:26 3XHCN42 systemd[1]: Started Update resolvconf for networkd DNS.
Dec 9 12:09:16 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 12:16:37 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 7 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 12:17:01 3XHCN42 CRON[21633]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 12:17:40 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 12:41:49 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 23 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 12:42:18 3XHCN42 systemd-timesyncd[1498]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com).
Dec 9 12:42:52 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 12:55:28 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 12 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 12:55:41 3XHCN42 systemd[1]: Starting Automatically fetch and run repair assertions…
Dec 9 12:55:43 3XHCN42 systemd[1]: Started Automatically fetch and run repair assertions.
Dec 9 12:56:31 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 13:16:28 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 19 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 13:17:01 3XHCN42 CRON[25233]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 13:17:31 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 14:16:19 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 56 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 14:17:01 3XHCN42 CRON[28819]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 14:17:22 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 15:16:10 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 56 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 15:17:01 3XHCN42 CRON[32411]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 9 15:17:13 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 16:06:34 3XHCN42 wpa-supplicant.wpa[1881]: message repeated 47 times: [ wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1]
Dec 9 16:06:50 3XHCN42 snapd[1947]: storehelpers.go:436: cannot refresh: snap has no updates available: “alsa-utils”, “bluez”, “caracalla”, “caracalla-kernel”, “ccm-wda”, “dcc”, “dcm”, “locationd”, “modem-manager”, “network-manager”, “tpm2”, “udisks2”, “uefi-fw-tools”, “wifi-ap”, “wpa-supplicant”
Dec 9 16:07:37 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 16:08:07 3XHCN42 systemd[1]: Reloading.
Dec 9 16:08:08 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-120.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:08 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-118.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:08 3XHCN42 systemd[1]: [/etc/systemd/system/snap-core-8039.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:08 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-121.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:09 3XHCN42 systemd[1]: Reloading.
Dec 9 16:08:09 3XHCN42 systemd[1]: [/etc/systemd/system/snap-core-8213.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:09 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-120.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:09 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-118.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:09 3XHCN42 systemd[1]: [/etc/systemd/system/snap-core-8039.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:09 3XHCN42 systemd[1]: [/etc/systemd/system/snap-caracalla\x2dkernel-121.mount:10] Unknown lvalue ‘LazyUnmount’ in section ‘Mount’
Dec 9 16:08:10 3XHCN42 systemd[1]: Starting Message of the Day…
Dec 9 16:08:10 3XHCN42 systemd[3267]: motd-news.service: Failed at step EXEC spawning /etc/update-motd.d/50-motd-news: No such file or directory
Dec 9 16:08:10 3XHCN42 systemd[1]: motd-news.service: Main process exited, code=exited, status=203/EXEC
Dec 9 16:08:10 3XHCN42 systemd[1]: Failed to start Message of the Day.
Dec 9 16:08:10 3XHCN42 systemd[1]: motd-news.service: Unit entered failed state.
Dec 9 16:08:10 3XHCN42 systemd[1]: motd-news.service: Failed with result ‘exit-code’.
Dec 9 16:08:10 3XHCN42 systemd[1]: Mounting Mount unit for core, revision 8213…
Dec 9 16:08:10 3XHCN42 systemd-udevd[572]: Network interface NamePolicy= disabled on kernel command line, ignoring.
Dec 9 16:08:10 3XHCN42 systemd[1]: Mounted Mount unit for core, revision 8213.
Dec 9 16:08:13 3XHCN42 dbus[1765]: [system] Reloaded configuration
Dec 9 16:08:13 3XHCN42 dbus[1765]: [system] Reloaded configuration
Dec 9 16:08:13 3XHCN42 snapd[1947]: spec.go:175: renaming mount entry for directory “/var/snap/ccm-wda/20” to “/var/snap/ccm-wda/20-2” to avoid a clash
Dec 9 16:08:13 3XHCN42 snapd[1947]: spec.go:175: renaming mount entry for directory “/var/snap/ccm-wda/20” to “/var/snap/ccm-wda/20-3” to avoid a clash
Dec 9 16:08:14 3XHCN42 kernel: [415440.136313] audit: type=1400 audit(1575907694.424:177): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.core.hook.configure” pid=3353 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.161800] audit: type=1400 audit(1575907694.448:178): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap-update-ns.core” pid=3355 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.557553] audit: type=1400 audit(1575907694.844:179): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.aconnect” pid=3358 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.568132] audit: type=1400 audit(1575907694.856:180): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap-update-ns.alsa-utils” pid=3357 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.576780] audit: type=1400 audit(1575907694.864:181): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.alsa-restore” pid=3359 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.591264] audit: type=1400 audit(1575907694.880:182): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.alsabat” pid=3360 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.595005] audit: type=1400 audit(1575907694.880:183): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.alsactl” pid=3361 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.601954] audit: type=1400 audit(1575907694.888:184): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.alsaloop” pid=3362 comm=“apparmor_parser”
Dec 9 16:08:14 3XHCN42 kernel: [415440.614137] audit: type=1400 audit(1575907694.900:185): apparmor=“STATUS” operation=“profile_replace” profile=“unconfined” name=“snap.alsa-utils.alsamixer” pid=3363 comm=“apparmor_parser”
Dec 9 16:08:18 3XHCN42 snapd[1947]: daemon.go:540: gracefully waiting for running hooks
Dec 9 16:08:18 3XHCN42 snapd[1947]: daemon.go:542: done waiting for running hooks
Dec 9 16:08:21 3XHCN42 snapd[1947]: daemon.go:643: Waiting for system reboot
Dec 9 16:08:40 3XHCN42 wpa-supplicant.wpa[1881]: wlan0: CTRL-EVENT-SCAN-FAILED ret=-16 retry=1
Dec 9 16:09:21 3XHCN42 systemd[1]: Removed slice system-console\x2dconf.slice.
Dec 9 16:09:21 3XHCN42 systemd[1]: Unmounting /etc/writable…
Dec 9 16:09:21 3XHCN42 systemd[1]: Removed slice system-serial\x2dconsole\x2dconf.slice.
Dec 9 16:09:21 3XHCN42 systemd[1]: Closed Load/Save RF Kill Switch Status /dev/rfkill Watch.
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopped target Graphical Interface.
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopped target Multi-User System.
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping LSB: Set the CPU Frequency Scaling governor to “ondemand”…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopped target Login Prompts.
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application udisks2.udisksd…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Login Service…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-347.service…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping OpenBSD Secure Shell server…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Ubuntu FAN network setup…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application ccm-wda.wda…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application locationd.run…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-368.service…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application modem-manager.modemmanager…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-345.service…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application udisks2.ciborium…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application epi-gateway.main…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application dcm.omiserver…
Dec 9 16:09:21 3XHCN42 ModemManager[1891]: Caught signal, shutting down…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping D-Bus System Message Bus…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application bluez.bluez…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application network-manager.networkmanager…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application uefi-fw-tools.fwupd…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Serial Getty on ttyS0…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Getty on tty1…
Dec 9 16:09:21 3XHCN42 systemd[1]: Stopping Service for snap application epi-zaphost.zaphost…
Dec 9 16:09:21 3XHCN42 NetworkManager[1926]: [1575907761.9436] caught SIGTERM, shutting down normally.
Dec 9 16:09:21 3XHCN42 systemd[1]: Starting Ubuntu core (all-snaps) system shutdown helper setup service…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-424.service…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping Cgroup management daemon…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping Service for snap application ccm-wda.cloudled…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping Service for snap application wifi-ap.management-service…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-346.service…
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping Regular background program processing daemon…
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Check File [/var/snap/epi-zaphost/x1/config/ZapHost.config]
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: NCP Config 1
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: Baud 115200
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: RTS/CTS
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: In Block Size 256
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: Out Block Size 1
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: Trying Port /dev/ttyS4
Dec 9 16:09:22 3XHCN42 epi-zaphost.zaphost[1910]: Init: Base Port 4900
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped target Timers.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped Daily Cleanup of Temporary Directories.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped Message of the Day.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped Timer to automatically fetch and run repair assertions.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped target System Time Synchronized.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopped target Bluetooth.
Dec 9 16:09:22 3XHCN42 systemd[1]: Stopping snap.caracalla.interface.gpio-425.service…
Dec 9 06:25:02 3XHCN42 rsyslogd: message repeated 4 times: [ [origin software=“rsyslogd” swVersion=“8.16.0” x-pid=“1752” x-info=“http://www.rsyslog.com”] rsyslogd was HUPed]
Dec 9 16:09:23 3XHCN42 rsyslogd: [origin software=“rsyslogd” swVersion=“8.16.0” x-pid=“1752” x-info=“http://www.rsyslog.com”] exiting on signal 15.
Dec 11 10:12:25 3XHCN42 rsyslogd: [origin software=“rsyslogd” swVersion=“8.16.0” x-pid=“1881” x-info=“http://www.rsyslog.com”] start
Dec 11 10:12:25 3XHCN42 rsyslogd-2222: command ‘KLogPermitNonKernelFacility’ is currently not permitted - did you already set it via a RainerScript command (v6+ config)? [v8.16.0 try http://www.rsyslog.com/e/2222 ]
Dec 11 10:12:25 3XHCN42 rsyslogd: rsyslogd’s groupid changed to 114
Dec 11 10:12:25 3XHCN42 rsyslogd: rsyslogd’s userid changed to 108
Dec 11 10:12:25 3XHCN42 rsyslogd-2039: Could not open output pipe ‘/dev/xconsole’:: No such file or directory [v8.16.0 try http://www.rsyslog.com/e/2039 ]
Dec 11 10:12:25 3XHCN42 rsyslogd-2007: action ‘action 10’ suspended, next retry is Wed Dec 11 10:12:55 2019 [v8.16.0 try http://www.rsyslog.com/e/2007 ]
Dec 11 10:12:25 3XHCN42 kernel: [ 0.000000] microcode: CPU0 microcode updated early to revision 0x90c, date = 2019-04-23
Dec 11 10:12:25 3XHCN42 kernel: [ 0.000000] Initializing cgroup subsys cpuset
Dec 11 10:12:25 3XHCN42 kernel: [ 0.000000] Initializing cgroup subsys cpu

Dec 9 16:08:10 3XHCN42 systemd[1]: Mounting Mount unit for core, revision 8213…
Dec 9 16:08:10 3XHCN42 systemd-udevd[572]: Network interface NamePolicy= disabled on kernel command line, ignoring.
Dec 9 16:08:10 3XHCN42 systemd[1]: Mounted Mount unit for core, revision 8213.
Dec 9 16:08:13 3XHCN42 dbus[1765]: [system] Reloaded configuration
Dec 9 16:08:13 3XHCN42 dbus[1765]: [system] Reloaded configuration
...
Dec 9 16:08:18 3XHCN42 snapd[1947]: daemon.go:540: gracefully waiting for running hooks
Dec 9 16:08:18 3XHCN42 snapd[1947]: daemon.go:542: done waiting for running hooks
Dec 9 16:08:21 3XHCN42 snapd[1947]: daemon.go:643: Waiting for system reboot

Looks like the core snap got refreshed. Can you obtain the output of snap changes? This will contain more meaningful information. If it was part of auto-refresh, then snap change --last=auto-refresh will show the detailed log of the most recent change of that kind.

Yes I will get that information. It is on a remote site so not immediately available to me. Will get back asap.

Here is the output from snap changes and snap change --last=auto-refresh :

admin@7PTJL42:~$ snap changes

ID Status Spawn Ready Summary

1910 Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Auto-refresh snap “core”

1911 Done yesterday at 15:07 UTC yesterday at 15:07 UTC Connect ccm-wda: cloud-led to caracalla:cloud-led

1912 Done yesterday at 15:07 UTC yesterday at 15:07 UTC Connect ccm-wda: sku-bit-a to caracalla:sku-bit-a

1913 Done yesterday at 15:07 UTC yesterday at 15:07 UTC Connect ccm-wda: sku-bit-b to caracalla:sku-bit-b

1914 Done yesterday at 15:07 UTC yesterday at 15:07 UTC Connect ccm-wda: sku-bit-c to caracalla:sku-bit-c

admin@7PTJL42:~$ snap change --last=auto-refresh

Status Spawn Ready Summary

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:42 UTC Ensure prerequisites for “core” are available

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Download snap “core” (8213) from channel “stable”

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Fetch and check assertions for snap “core” (8213)

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Mount snap “core” (8213)

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Run pre-refresh hook of “core” snap if present

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Stop snap “core” services

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Remove aliases for snap “core”

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Make current revision for snap “core” unavailable

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Copy snap “core” data

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Setup snap “core” (8213) security profiles

Done 3 days ago, at 23:42 UTC 3 days ago, at 23:43 UTC Make snap “core” (8213) available to the system

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Automatically connect eligible plugs and slots of snap “core”

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Set automatic aliases for snap “core”

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Setup snap “core” aliases

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Run post-refresh hook of “core” snap if present

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Start snap “core” (8213) services

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Remove data for snap “core” (7713)

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Remove snap “core” (7713) from the system

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Clean up “core” (8213) install

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Run configure hook of “core” snap if present

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Run health check of “core” snap

Done 3 days ago, at 23:42 UTC yesterday at 15:07 UTC Consider re-refresh of “core”

Make snap “core” (8213) available to the system

2019-12-09T23:43:57Z INFO Requested system restart.

Automatically connect eligible plugs and slots of snap “core”

2019-12-09T23:44:24Z INFO Waiting for restart…

2019-12-09T23:44:24Z INFO Waiting for restart…

2019-12-09T23:44:24Z INFO Waiting for restart…

2019-12-09T23:44:24Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

2019-12-09T23:44:25Z INFO Waiting for restart…

Consider re-refresh of “core”

2019-12-11T15:07:18Z INFO No re-refreshes found.

admin@7PTJL42:~$

I’m guessing it’s a different host than previously (7PTJL42 vs 3XHCN42 in the logs), so the date/time may not line up. Both devices apparently received an update of the core snap, what normally triggers a reboot, this is expected.

Again, from the logs:

Status Spawn                     Ready                    Summary
Done   3 days ago, at 23:42 UTC  3 days ago, at 23:43 UTC Make snap “core” (8213) available to the system
Done   3 days ago, at 23:42 UTC  yesterday at 15:07 UTC   Automatically connect eligible plugs and slots of snap “core”
Done   3 days ago, at 23:42 UTC  yesterday at 15:07 UTC   Set automatic aliases for snap “core”

There’s clearly a gap between the time when Make snap "core" available.. and Automatically connect.. tasks finished.

However, snapd only triggers the reboot to start. The actual reboot heavy-lifting is performed accordingly by systemd and the kernel, using appropriate methods for your particular hardware.

I would suggest checking first if the reboot works correctly when you issue it from the command line on those devices. Make sure to rule out trivial things, eg. something connected to the seriel console that could trigger grub to get stuck in the boot prompt.